<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <div id="app"></div>
  <script src="http://unpkg.com/vue@next"></script>
  <script>
    const app = Vue.createApp({
      template: `<h2>123</h2>`
    })
    app.mount("#app")
  </script>
</body>
</html>